Treatment of cellulosic textile materials



.7 2,839,429 Ice Patented June 17, 1958 TREATMENT OF CELLULOSIC TEXTILE MATERIALS John Thompson Marsh, Hale, George Bell, Manchester, and Alec Geoffrey Thompson, Whitefield, England, assignors to Tootal Eroadhurs't Lee Company Limited, Manchester, England, a British company No Drawing. Application August 31, 1953 Serial No. 377,714

Claims priority, application Great Britain October 31, 1949 5 Claims. (Ci. 117-1314) The present invention relates to the treatment of textile materials in orer to improve their crease resistance.

This application is a continuation-in-part of application Serial No. 191,931 filed October 24, 1950, and now abandoned.

The invention may be applied to cellulosic textile material made from natural or regenerated fibres or mixtures of these with one another or with non-cellulosic fibres. It may be applied to fibres in loose state or inthe form of rovings or slubbings, but is preferably applied to yarns, woven fabrics, knitted fabrics and manufactured garments.

It is well known that the resistance to creasing of cellulosic textile materials can be considerably improved by impregnating them with an aqueous solution containing a crystalloidal intermediate condensation product of a synthetic resin and then insolubilising the synthetic resin by heating the impregnated material. Although this procedure improves the resistance to creasing of the textile materials when dry, i. e. makes them dry crease-resisting, it still leaves them highly susceptible to creasing when wet or when under conditions of high humidity.

An object of the present invention is to improve the resistance to creasing of cellulosic textile materials when wet or when under conditions of high humidity, i. e. to make them wet crease-resisting.

A further object of the invention is to render a cellulosic fabric, especially a regenerated cellulose fabric, dry crease-resisting and wet crease-resisting.

We have found that these objects can be secured by insolubilising in the textile materials a synthetic resin and by also rendering infusible in the textile materials a polysiloxane oil.

,. Although it is known that textile materials can be made water-repellent by rendering a polysiloxane oil infusible on the fibres it was quite unexpected and could not have been predicted that by also insolubilising a synthetic resin in the materials they would be rendered crease-resisting under conditions of high humidity and under wet conditions. Textile materials rendered waterrepellent by polysiloxanes are much difiicult to wet than textile materials not so treated and this is, indeed, what is meant by the term water-repellent. They can, however, be wet by water if they are suitably treated e. g. with the aid of wetting agents; and when thoroughly wet out they absorb just as much water as they would do before treatment with the polysiloxane. Textile materials which have had synthetic resin insolubilised therein and polysiloxane rendered infusible on the fibres are, indeed, water-repellent but since they also absorb, when fully wet out, just as much water as textile materials not containing the polysiloxane but otherwise identical, it would not have been expected that their susceptibility to creasing would have been any different in the wet state. Most surprisingly, the textile materials so treated have been found to have much improved resistance to creasing in the wet state. This is of great practical value because it not only reduces the susceptibility of the materials to become creased during laundering but is also reduces their susceptibility to become creased in atmospheres of high humidity.

In carrying out the invention, the textile materials are impregnated with an aqueous solution containing a crystalloidal intermediate condensation product of a synthetic resin of the group consisting of condensation products of formaldehyde with urea, condensation products of formaldehyde with melamine and condensation prod nets of formaldehyde with phenol and also with an aqueous dispersion of a polysiloxane oil which on heating in thin layers gives an infusible non-tacky flexible film and are heated to insolubilise said synthetic resin and to render said polysiloxane oil infusible.

Although it is most convenient to use a single impregnating solution, it is also possible to obtain dry creaseresistance and wet crease-resistance by applying the aqueous solution of the intermediate condensation product of the synthetic resin and an aqueous dispersion of polysiloxane oil in successive steps in either order provided that the textile material is heated between the two steps to insolubilise the synthetic resin or to render the polysiloxane infusible as the case may be. When successive treatment is effected, the polysiloxane oil may be used as a solution in an organic solvent instead of as an aqueous dispersion. Also, if successive treatment is effected it is preferred that the treatment with polysiloxane oil be eifected first and in this case it is necessary to wet out the textile material thoroughly before impregnation with the intermediate condensation product of synthetic resin.

The polysiloxanes are sometimes referred to as sillcones.

They can be formed from various alkyl chlorosilanes or arylchlorsilanes with or without silicon tetrachloride by hydrolysis and co-condensa'tion whereby all the chlorine atoms are replaced by hydroxyl groups certain of which condense together with elimination of water. The structures of the resulting silic ones are not clearly understood but it is believed that they consist of silicon-oxygen chains arranged in a network, the crosslinking of which takes place through oxygen atoms and in which the substituents, which may all be organic radicals or of which some may be organic radicals and some hydrogen atoms, are linked to silicon atoms. The mechanical properties of the solid polymers are believed to depend in a large part upon the extent of the crosslinking and the length of the linear chains in the network, as well as on the nature of the substituents. For example, polysiloxanes called methyl silicones can be prepared by mixing dimethyl dichlorsilane with methyl trichlorsilane or silicon tetrachloride and then effecting hydrolysis and cocondensation. As the ratio of CH radicals to Si atoms varies from 1.2 to 1.7 in different members of the series, the methyl silicones change from sticky syrups (which cure rapidly on heating to brittle solids) to oily liquids (which cure slowly to soft, flexible solids). In the analogous series of resins in which the methyl radical is replaced by the ethyl radical, a. similar change in properties is observed but these co-called ethyl silicones are, in general, softer and slower curing. than the corresponding methyl silicones.

The general structure and properties of the polysiloxanes which are commonly called silicone polymers are described in An Introduction to the Chemistry of the Silicones" by Eugene G. Rochow published by John Wiley and Sons Inc. of New York. The second edition of this book (1951) discusses the structure of alkyl. silicones on pages 78 to 101, of aryl silicones on pages 101 to 104 and of 104 to 107.

alkyl-aryl silicones on pages r assaaae As stated above, the methyl silicones can be prepared from dimethyl dichlorsilane. Similarly, polysiloxanes called methyl hydrogen silicones can be prepared by hydrolysis of methyl hydrogen dihalogenosilanes.

Accordingly, the silicones employed in the present invention are polysiloxane o-ils containing a multiplicity of the structural units llti 3|1 O R2 where R is an alkyl group or an aryl group or hydrogen or oxygen and R is an alkyl group or an aryl group. Preferably there is employed a polysiloxane oil containing a multiplicity of the structural units -Si 3 3 On account of the ability of the intermediate hydrolysis products of the alkyl or aryl halogenosilanes to undergo co condens'ation, resins may be obtained having different R/Si ratios (R representing alkyl or aryl groups or hydrogen atoms) giving them a wide range of properties. The polysiloxane oils employed in the present invention are those in which the total R/Si ratio is high enough to avoid the development to a marked degree of resinous adhesive properties as evidenced by the production of coated yarns and other undesirable effects in the treated textiles, i. e., the polysiloxane should possess an oily rather than a tacky nature, but, nevertheless, low enough to enable the condensation to the solid state to be achieved in a. reasonable time and at a temperature not detrimental to a textile fibre. These polysiloxanes appear to have mean molecular weights ranging from a few hundred to twenty thousand or so but those which have been found most convenient for use in the present invention have a mean molecular weight of the order of one thousand and a viscosity of 25 C. of the order of to stokes.

We have found that the polysiloxanes which are oily liquids spread uniformly over the surface of the fibres providing that the viscosity at C. of the oil does not exceed about 1,000 stokes, giving a marked freedom from coated yarn efiects and possessing a high degree of flexibility in the cured state. On the other hand, the products known as silicone varnishes, which are viscous tacky syrups generally used dissolved in an organic solvent, do not give the same uniformity of coating, give rise to undesired coated yarn efiects and are exceedingly hard and brittle when cured. Examples of products commercially available are the methyl hydrogen polysiloxane oils sold under the trade name Silicone-Fluid DC 1107 and DeCetex 104 both made by the Dow Corning Corporation of the United States of America.

The amount of synthetic resin introduced into the textile material by insolubilisation of the intermediate condensation product depends upon the degree of effect desired, the nature of the resin and the nature of the textile material. An improvement in dry crease-resistance can be obtained when the amount of synthetic resin is from about 3% to about based on the weight of dry textile material. In the case of ureaformaldehyde resin, the most useful improvement in dry crease-resistance is obtained with from about 8% to about 30% based on the weight of dry textile material. Equivalent effects are obtained with about half these amounts of melamine-formaldehyde resins i. e. the most useful improvement in dry crease-resistance is obtained with from about 4% to about 20% based on the weight of dry textile material. Phenolformaldehyde resins are intermediate in their effect, the most useful improvement in dry. crease-resistance being obtained'with from about 6% to about 25 based on the weight of dry textile material. The amount of synthetic resin intermediate condensation product contained in the impregnated material before insolubilisation should be higher than the content of insoluble resin desired in the textile material by about one quarter, i. e. amount of synthetic resin intermediate condensation product contained in the impregnated material before insolubilisation should be about 4% to about 37% based on the weight of dry textile material, i. e. about 10% to about 37% in the case of an intermediate condensation product of a urea-formaldehyde resin and about 5% to about 30% in the case of an intermediate condensation product of a melamine-formaldehyde resin. The concentration of intermediate condensation product in the impregnating liquor depends upon the degree of expression of liquor from the textile material. It is generally most convenient to impregnate the textile material with the liquor and then squeeze it until it com tains its own weight of liquor. However it may be squeezed so as to contain more or less than its own weight of liquor and in all cases the concentration of the liquor will be so chosen that for the degree of expression adopted the material will contain such an amount of condensation product as will give the desired amount of insolubilised synthetic resin from about 3% to about 30% based on the weight of dry textile material. It is quite easy to calculate in any given case the concentration of liquor required and this is commonly done in the textile finishing trade.

The amount of polysiloxane introduced into the textile material by rendering the polysiloxane oil infusible similarly depends upon the degree of effect desired and the nature of the'textile material. A useful improvement in wet crease-resistance can be obtained when the amount of infusible polysiloxane is from about 2% to about 15% based on the weight of dry textile material. Accordingly, the amount of polysiloxane oil contained in the impregnated material should be about 2% to about 15% based on the weight of dry textile material. As with the solution of intermediate condensation product, the concentration of polysiloxane oil in the impregnating liquor depends upon the degree of expression of liquor from the textile material. In all cases the concentration of liquor will be so chosen that for the degree of expression adopted the material will contain such an amount of polysiloxane oil as will give the desired amount of infusible polysiloxane from about 2% to about 15% based on the weight of-dry textile material.

The amount of insolubilised synthetic resin and infusible polysiloxane in the textile material should not together exceed about 32% based on the weight of dry textile material. As a rule, it will be most convenient for the amount of infusible polysiloxane in the textile material to be from about one third of to about the same as the amount of insolubilised resin. Generally speaking an amount of insolubilised urea-formaldehyde resin between about 12% and about 20%, for example about 15%, based on the Weight of dry textile material, will give a useful improvement in dry crease-resistance. To secure these amounts of insolubilised resin the amount of urea-formaldehyde intermediate condensation product contained in the impregnated material before insolubilisation should be about 16% to about 25% for example about 20%, based on the weight of dry textile material. Thus, if a single impregnating liquor containing the syn thetic resin intermediate condensation product and the polysiloxane oil is used the total amount of said intermediate condensation product and of said polysiloxane oil contained in the impregnated material, before heat ing to insolubilise the synthetic resin and render the polysiloxane oil infusible, should not exceed about 39% based on the dry weight of textile material.

The crystalloidal intermediate condensation product of a synthetic resin may be obtained by the treatment of formaldehyde with urea in aqueous solution for no more than suflicient time to produce a solution of a crystalloidal methylol compound. Instead of a urea-formaldehyde crystalloidal intermediate condensation product, a melamine-formaldehyde crystalloidal intermediate condensation product may be used. In either case, one may employ an ether of the methylol compounds of urea, or melamine, alone or in admixture with the methylol compound itself, and one may also use mixtures of ureaforrnaldehyde intermediate condensation products and melamine-formaldehyde intermediate condensation products as well as mixtures of their ethers.

The crystalloidal intermediate condensation product of a synthetic resin need not be an amino aldehyde condensation product. It may be, for example, a phenol formaldehyde condensation product.

A suitable synthetic resin crystalloidal intermediate condensation product to employ is a solution of ureaformaldehyde condensation product of low molecular weight and capable, of penetrating textile fibres prepared according to British Patent No. 449,243.

Although the crystalloidal intermediate condensation product of a synthetic resin is employed in the form of an aqueous solution, such solution may have colloidal intermediate condensation product dispersed therein but the amount of the latter must not be suflicient to nullify the improvement in dry crease-resistance and wet creaseresistance of the cellulosic textile materials, brought about by the synthetic resin and the polysiloxane.

The aqueous solution of crystalloidal intermediate condensation product of a synthetic resin should also contain a catalyst suitable for completing the condensation of the synthetic resin intermediate condensation product on heating. Catalysts suitable for completing the condensation of amino-aldehyde condensation products may be substances of acid character or of a potentially acid character by which wemean a compound, such as the ammonium salt of an acid, which in the course of the heating decomposes and liberates free acid. Thus, the catalyst may be an acid, a mixture of acids or a mixture of an acid and a salt, but as stated above, it is preferably a substance which is capable of becoming acid (or more acid) during the treatment; instead of the ammonium salts mentioned, there are other substances such as aluminium chloride and zinc nitrate which can be used.

The solution or aqueous dispersion of polysiloxane oil may contain a catalyst for rendering the polysiloxane oil infusible. Such catalysts, for example zinc naphthena'te, are generally insoluble in water. If, as is preferred, an aqueous dispersion of, polysiloxane oil is used, the catalyst can be incorporated, if necessary with the aid of an organic solvent, in the polysiloxane oil before the latter is dispersed in the aqueous liquid used for impregnation of the textile material or it can be dispersed in the aqueous liquid separately. The polysiloxane oil may be dissolved in a volatile organic solvent and the resulting solution dispersed in the aqueous liquor for the impregnation of the textile material. We have found that metal stearates such as calcium, zinc or cobalt stearate are suitable catalysts for the curing of polysiloxanes.

As already stated, the cellulosic textile material may be impregnated separately with the water-soluble crystalloidal intermediate condensation product of a synthetic resin and with the polysiloxane oil and heated after each impregnation but is preferably impregnated with both to gether and subjected to a single heating.

The heating of the impregnated textile material to render the crystalloidal intermediate condensation product of the synthetic resin insoluble and the polysiloxane oil infusible is preferably effected in presence of a catalyst or catalysts for the further condensation of the synthetic resin or for the further condensation of the polysiloxane oil or for both.

The impregnated and dried fabric can be heated in ditferent ways and the most suitable time and temperature of heating will depend upon the nature of the intermediate condensation product, the nature of the catalyst used for the condensation, the nature of the polysiloxane oil and the nature of the catalyst, if any, used for rendering the polysiloxane oil infusible. In general, however, when using a weak acid catalyst for the synthetic resin condensation the temperature may be from about 160 to about 180 C. but when using a stronger acid catalyst or a substance capable of liberating stronger acid, the temperature may be only about to about 150 C. Although a time of 3 to 5 minutesat these temperatures will suflice to insolubilise the synthetic resin, a time of about 5 minutes to about 20 minutes is required to render the polysiloxane oil infusible.

If, therefore, a textile material is impregnated with a liquor containing the crystalloidal intermediate condensation product of a synthetic resin and the polysiloxane oil and then dried and subjected to a single heating, the time of heating should be about 5 minutes to about 20 minutes at a temperature of about to about 200 C. A time of about 10 to about 15 minutes at a temperature of about to about C. is quite suitable.

The textile material to be treated must be thoroughly absorbent so as to imbibe the amino aldehyde crystalloidal intermediate condensation products; with rayon materials it may be advisable to give a preliminary treatment with alkaline solutions and with cotton and linen it may be necessary to mercerise the materials to be treated by the invention in order to obtain the maximum absorptive capacity. During the drying of the prepared materials before impregnation, care is needed lest the temperature or other conditions of dryingsnould reduce the absorptive capacity. It may even be desirable to treat the swollen materials in the wet state.

It is also possible to incorporate other substances in the impregnating bath and so produce combined effects in one treatment; examples of this are inert fillers, colloidal dispersions, delustring agents and pigments. indeed, the present invention may be employed with advantage in pigment printing. It is possible to incorporate latices of natural and synthetic rubbers and other dispersions of polymers with the impregnating liquor where these are or have been made compatible.

The drying of the material when impregnated with intermediate condensation products of synthetic resins requires care and for best effects the goods should not be unduly stretched during drying as this not only interferes with the softness of the material but may even produce embrittlement. The conditions of temperature and humidity within the drying chamber should be such that there is no tendency, or only as little tendency as possible, for the synthetic resin intermediate condensation product to diffuse towards the surface during the drying operation.

It is possible, during or'immediately after the drying operation, to give mechanical treatment to the impregnated textile material. For example, it is possible to shrink the fabric by drying on a stenter equipped with an over-feed device or on a special machine for producing controlled compressive shrinkage. During or after drying, the material impregnated with intermediate condensation products of synthetic resins can .be subjected to mechanical distortion which is rendered permanent by the subsequent insolubilising treatment. For example, it is possible to calender the impregnated fabric during or after the drying operation, to emboss it, to Schreiner it or to produce glazed effects by friction as well as other properties. With some of the machines employed for the above purposes it is possible to produce the mechanical effect and complete the condensation by heating at one and the same time.

The following are examples of methods of carrying out the invention.

Example I 1) A methylol urea solution is made by heating 7 for 3 minutes at the boiling point under a reflux condenser The product is cooled and gm. of tartaric acid dissolved in 20 ml. of water is added.

(2) A polysiloxane oil emulsion is made by mixing 60 ml. of water containing 0.25 gm. glacial acetic acid and 2.5 gm. of trimethylbenzyl ammonium chloride in a high speed stirrer with 50 gm. of methyl hydrogen siloxane having a mean molecular Weight of the order of 1000 and then adding 1 gm. of calcium stearate dissolved in ml. xylene.

The emulsion so obtained is then homogenised by any of the conventional methods, e. g. by pumping through a spring loaded valve having accurately ground seats.

(3) The methylol urea solution 1 and the polysiloxane oil emulsion 2 are mixed and the volume of the mixture adjusted to 1000 ml. with water. A cotton fabric is padded with the liquor so as to obtain an absorption of about 100%. The cloth is dried at 60 C. and then baked at 160 C. for 10 minutes. It is now given a light wash in 0.25% soap solution at 50 C. followed by rinsing in water and drying. The urea-resin to polysiloxane ratio in the fabric is about 3 to 1 and the urea-resin content about 14.5% based on the weight of dry fabric.

Example 2 (1) A methylol melamine solution is made by heating at 70 C. at pH 8.5 a mixture of 30 melamine 54 gm. 37 wt. percent formaldehyde.

The required pH is secured by addition of caustic soda. After it has become clear, the mixture is heated at the same temperature for a further minutes; 18 gm. of 37 wt. percent formaldehyde, the pH of which has been previously adjusted to 8.0 with caustic soda, is now added and the reaction allowed to proceed for a further 15 minutes with the temperature maintained at 70-75 C. The product is now cooled and a solution of 5 gm. ammonium chloride and 15 ml. 0.88 S. G. aqueous ammonia is added.

(2) A polysiloxane oil emulsion is prepared as described in Example 1, Section 2.

(3) The methylol melamine solution 1 and the polysiloxane oil emulsion 2 are mixed and the volume made 1000 ml. by the addition of water. A regenerated cellulose fabric is padded with the liquor to obtain an absorption of about 100%. The cloth is dried at 60 C., baked at 150 C. for 10 minutes and then washed in 0.25% soap solution at 50 C. It is now rinsed with water and dried. The melamine-resin to polysiloxane ratio in the fabric is about 1 to l and the melamine-resin content about 4% based on the weight of dry fabric.

Example 3 (1) A methylol urea solution is made as described in Example 1, Section 1.

(2) A polysiloxane oil emulsion is made by mixing in a high speed stirrer 50 gm. of methyl hydrogen siloxane having a mean molecular weight of the order of 1000 1 gm. of zinc ethyl hexoate dissolved in 10 ml. xylene 0.25 gm. glacial acetic acid 2.5 gm. of an ethylene oxide condensate having the constitution RO(CH CH O),,H, where R is a fatty alcohol radical, e. g. oleyl, and n is 20.

After thorough mixing, a quantity of water approximately equal to the volume of the mixture is added and mixing continued. The emulsion so obtained is homogenised by any of the conventional methods, e. g. by pumping through a spring loaded valve having accurately ground seats.

(3) The methylol urea solution 1 and the polysiloxane oil emulsion 2 are mixed and the volume adjusted to 1000 ml. with water. A regenerated cellulosefabric is padded with the liquor so as to obtain a liquor absorption of about 100%. The fabric is dried at 60 C., baked at 160 C. for 10 minutes. It is now given alight wash in 0.25% soap solution at 50 C. followed by rinsing in water and drying. The urea-resin to polysiloxane ratio in the fabric is about 3 to 1 and the urea-resin content about 14.5% based on the weight of dry fabric.

Example 4 1) A phenol formaldehyde resin solution is made by heating 50 gm. phenol gm. 37 Wt. percent formaldehyde, and 1.5 gm. caustic soda dissolved in 3.0 ml. water,

at the boiling point for 10 minutes. The solution is now cooled and the pH adjusted to 4.0 by the addition of hydrochloric acid.

(2) A polysiloxane oil emulsion is prepared as described in Example 1, Section 2.

(3) The phenol formaldehyde resin solution 1 and the polysiloxane oil emulsion 2 are mixed and the volume made 1000 ml. by the addition of water. A regenerated cellulose fabric is padded with the liquor to obtain an absorption of liquor of The cloth is dried at 60 C. and baked at C. for 15 minutes. It is now washed in soap solution at 50 C., rinsed in water and dried. The phenol-resin to polysiloxane ratio in the fabric is about 3 to 2 and the phenol-resin content about 7.5% based on the weight of dry fabric.

Example 5 (1) A methylol urea solution is made by heating for 3 minutes at the boiling point under a reflux condenser 60 gm. urea 130 gm. 37 wt. percent formaldehyde (pH adjusted to 7 with caustic soda) 4.8 gm. 0.88 S. G. aqueous ammonia.

The product is cooled and 8 gm. of ammonium tartrate dissolved in 20 ml. water added.

The pH is adjusted to 8.5 with caustic soda. The reaction is allowed to proceed for 5 minutes, after which, without interrupting the boiling, the pH is made 5 by the addition of phopshoric acid and the reaction is allowed to proceed under these conditions for a further 20 minutes. The product is now cooled and the pH adjusted to 7 by the addition of caustic soda.

(3) A polysiloxane oil emulsion is prepared as described in Example 1, Section 2.

(4) The methylol urea solution 1, the colloidal solution of urea formaldehyde resin 2 and the polysiloxane oil emulsion 3 are mixed together and the volume made up to 1000 ml. by the addition of water.

A regenerated cellulose fabric is padded with the liquor to obtain an absorption of about 100%. The cloth is dried at 60 C. and then baked at C. for 10 minutes. It is now given a light wash in 0.25% soap solution, rinsed in water and dried. The urea-resin to polysiloxane ratio in the fabric is about 3 to 1 and the urea-resin content about 14% based on the Weight of dry fabric.

Various modifications may be made in the foregoing examples, which are purely illustrative, without departing from the invention. Thus, the solution of gm. of tartaric acid in 20 ml. of water used in Examples 1 and 3 may be replaced by a solution of 7.5 gm. zinc nitrate hexahydrate dissolved in 15 ml. of water; also the trimethylbenzyl ammonium chloride used in Examples 1, 2, 4 and 5 may be replaced by 2.5 gm. of sodium oleyl sulphate.

Moreover it is possible to modify each of the examples by impregnating the fabric first with the solution of synthetic resin intermediate condensation product of Section 1, diluted to 1000 mls. with water, and then drying and heating it at the temperatures and for the times indicated and then impregnating it with the dispersion of polysiloxane oil, diluted to 1000 mls. with water, followed by drying and heating at the same temperatures and for the same times. The first heating may be done at the temperatures given for even a shorter time of, say, 5 minutes. Alternatively, the impregnation may be first with the diluted dispersion of polysiloxane oil, followed by drying and heating, and then with the diluted solution of synthetic resin intermediate condensation product of synthetic resin, followed by drying and heating. In the latter case the fabric must be wet out very thoroughly after the first drying and heating; and in this latter case the second heating may be done at the temperatures given for even a shorter time of, say, 5 minutes. In either of these modifications of the examples, the fabric is padded with each liquor so as to obtain an absorption of 100%. In either modification, the wash in soap solution, rinsing in water and drying need only follow the second drying and heating.

The invention is not limited to the specific embodiments thereof hereinbefore described but is of the scope of the appended claims.

We claim:

1. The process for improving the wet crease-resistance properties of a cellulosic fabric comprising the steps of impregnating said material with an aqueous medium consisting essentially of water, a crystalloidal intermediate condensation product selected from the group consisting of urea-formaldehyde, melamine-formaldehyde and mixtures thereof, and a polysiloxane oil curable by heat to a solid infusible state selected from the group consisting of methyl hydrogen polysiloxane and ethyl hydrogen polysiloxane, said condensation product being present on said fabric in an amount of about 4 parts by weight for each part of said polysiloxane oil, drying the impregnated fabric and then subjecting said fabric to heat sufli cient to render said condensation product insoluble and said polysiloxane oil infusible.

2. The process for improving the wet crease-resistance properties of a cellulosic textile material comprising the steps of impregnating said material with an aqueous medium consisting essentially of water, a crystalloidal intermediate condensation product selected from the group consisting of urea-formaldehyde, melamine-formaldetit hyde and mixtures thereof, and a polysiloxane oil curable by heat to a solid infusible state selected from the group consisting of methyl hydrogen polysiloxane and ethyl hydrogen polysiloxane, said condensation product being present in an amount of about 20% by weight based on the dry weight of the textile material, said polysiloxane oil being present in an amount of 5% by weight based on the dry weight of the textile material, drying said treated material and subjecting the dried cellulosic textile material to heat sufiicient to render said condensation product insoluble and render said polysiloxane oil infusible.

3. The process for improving the wet crease-resistance properties of a cellulosic textile material comprising the steps of impregnating said material with an aqueous medium consisting essentially of water, a crystalloidal intermediate urea-formaldehyde condensation product and a methyl hydrogen polysiloxane oil curable by heat to a solid infusible state, said condensation product being present in an amount of about 20% by weight based on the dry weight of the textile material, said polysiloxane oil being present in an amount of 5% based on the dry weight of the textile material, drying said treated material and subjecting the dried cellulosic textile material to heat sufiicient to render said condensation product insoluble and render said polysiloxane oil infusible.

4. The process for improving the wet crease-resistance properties of a cellulosic textile material comprising the steps of impregnating said material with an aqueous medium consisting essentially of water, a crystalloidal intermediate urea-formaldehyde condensation product, a methyl hydrogen polysiloxane oil curable by heat to a solid infusible state, and a potentially acid catalyst for the further condensation of said urea-formaldehyde product consisting of a heat decomposable acid salt of ammonia, said condensation product being present in an amount of about 20% by weight based on the dry weight of the textile material, said polysiloxane oil being present a in an amount of 5% based on the dry weight of the textile material, drying said treated material and subjecting the dried cellulosic textile material to heat sufficient to render said condensation product insoluble and render said polysiloxane oil infusible.

5. The cellulosic fabric having improved wet creaseresistance properties made in accordance with the process defined in claim 1.

References Cited in the file of this patent UNITED STATES PATENTS 2,258,220 Rochow Apr. 27, 1940 2,258,222 Rochow Oct. 7, 1941 2,484,598 Weisberg et al Oct. 11, 1949 2,502,286 Sowa Mar. 28, 1950 2,612,482 Rasmussen Sept. 30, 1952 2,634,285 Rust Apr. 7, 1953 OTHER REFERENCES Modern Plastics, vol. 23, issue 7, pages -162, 192 and 194, published March 1946. 

1. THE PROCESS FOR IMPROVING THE WET CREASE-RESISTANCE PROPERTIES OF A CELLULOSIC FABRIC COMPRISING THE STEPS OF IMPREGNATING SAID MATERIAL WITH AN AQUEOUS MEDIUM CONSISTING ESSENTIALLY OF WATER, A CRYSTALLOIDAL INTERMEDIATE CONDENSATION PRODUCT SELECTED FROM THE GROUP CONSISTING OF UREA-FORMALDEHYDE, MELAMINE-FORMALDEHYDE AND MIXTURES THEREOF, AND A POLYSILOXANE OIL CURABLE BY HEAT TO A SOLID INFUSIBLE STATE SELECTED FROM THE GROUP CONSISTING OF METHYL HYDROGEN POLYSILOXANE AND ETHYL HYDROGEN POLYSILOXANE, SAID CONDENSATION PRODUCT BEING PRESENT ON SAID FABRIC IN AN AMOUNT OF ABOUT 4 PARTS BY WEIGHT FOR EACH PART OF SAID POLYSILOXANE OIL, DRYING THE IMPREGNATED FABRIC AND THEN SUBJECTING SAID FABRIC TO HEAT SUFFICIENT TO RENDER SAID CONDENSATION PRODUCT INSOLUBLE AND SAID POLYSILOXANE OIL INFUSIBLE. 